Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer in the United States and the fourth most prevalent cancer among men worldwide. The prognosis of HNSCC patients is relatively poor, due to the advanced nature of the disease at the time of diagnosis. HNSCC frequently metastasizes to the regional lymph nodes, and metastasis is the strongest predictor of disease prognosis and outcome. Current pre-operative clinical methods often misdiagnose the presence or absence of nodal metastasis and the current management of HNSCC commonly includes dissection of neck lymph nodes with pathologic examination.
Metastasis to lymph nodes in HNSCC (and other cancers) is frequently the strongest predictor of disease prognosis and outcome. Lymph nodes that contain tumor cells are designated “positive” lymph nodes. In advanced cases, positive lymph nodes become enlarged and can be detected by palpation. However, small positive nodes, such as nodes that contain tumor cells, but are not yet enlarged, are difficult to identify. Such nodes are referred to as containing “occult” disease. The difficulty of identifying whether a node is negative or contains occult disease complicates treatment decisions. In some cases, lymph nodes that turn out to be negative may be removed unnecessarily, while in other cases, lymph nodes that contain tumor cells are not removed. Other treatment decisions, such as whether to perform additional lymph node dissection and selection of adjuvant treatment are also based on nodal status.